Allow sending static/top-level functions through ports and as isolate

tests/isolate/illegal_msg_function_test.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library illegal_msg_function_test;
 
 import "dart:isolate";
 import "dart:async" show Future;
 import "package:unittest/unittest.dart";
 import "remote_unittest_helper.dart";
 
-funcFoo(x) => x + 2;
-
 echo(sendPort) {
   var port = new ReceivePort();
   sendPort.send(port.sendPort);
   port.listen((msg) {
     sendPort.send("echoing ${msg(1)}}");
   });
 }
 
 void main([args, port]) {
   if (testRemote(main, port)) return;
   test("msg_function", () {
-    var function = funcFoo;
+    var function = (x) => x + 2;
     ReceivePort port = new ReceivePort();
     Future spawn = Isolate.spawn(echo, port.sendPort);
     var caught_exception = false;
     var stream = port.asBroadcastStream();
     stream.first.then(expectAsync((snd) {
       try {
         snd.send(function);
       } catch (e) {
         caught_exception = true;
       }
 
       if (caught_exception) {
         port.close();
       } else {
         stream.first.then(expectAsync((msg) {
           print("from worker ${msg}");
         }));
       }
       expect(caught_exception, isTrue);
     }));
   });
 }